3 Important questions

What you believe will happen WILL be tested so that's why you need to ask your self these questions

#1
Many things can come your way to make you doubt the validity of your trade and the direction of the Market in your analysis, (peoples Ideas, a certain spike of volatility )

how many times have you got out of a trade brake even because of you questioned your trade with no determined goal of " if this happens THEN i will be a believer.

#2 this is where your stop loss should be (if you use one), and if you don't use a stop loss
you must already quantify your risk and reward (example: 2-1 risk vs reward my stop is 15 pips and my target is 30 pips, i will have 1 lot in the market so i will lose 150$ if i hit my stop loss)

#3 there's still an opportunity to make money if the market has gone against you, at what point will you be convinced that in this market condition you can make you money the other direction?( note this is a tricky question if your new to the markets, if your new learn how a price swing works.)

If you have asked the question and you feel uneasy or worried about your trade from any of the questions you have put to much at risk, you may be right! but what if your wrong.